Linear beam oscillating devices have been known and used to scan a laser beam back and forth in order to widen the effective beam operating area. A normal scanning device is only effective only in one oscillating direction of motion since the scanner generates a line instead of a circular path.
Beam spinners have become also known and used to spin a laser beam in a circular path in order to increase the effective width of the beam in all directions. It should be understood by the experts in the field that under spinning the actual diameter of the beam remains the same, and only its effective diameter on the workpiece is increased by the applied spinning. The known beam spinners with one or double optical means, however, must be set to a predetermined spin diameter before the actual operation and, must remain at that diameter until the beam and the apparatus is turned off and set to a different spin diameter. This has the drawback of repeated interruption of the operation, such as welding, each time a wider effective beam is necessary for the workpiece.